Hands-on Exercise 3B

4.1 Overview

In this hands-on exercise, I learn how to create animated statistical graphics.

I try two methods:

• gganimate
• plotly

4.2 Getting Started

4.2.1 Loading the R packages

pacman::p_load(readxl, gifski, gapminder,
               plotly, gganimate, tidyverse)

4.2.2 Importing the data

In this exercise, I use the Data worksheet from GlobalPopulation.xls.

col <- c("Country", "Continent")

globalPop <- read_xls("../data/GlobalPopulation.xls",
                      sheet = "Data") %>%
  mutate(across(col, as.factor)) %>%
  mutate(Year = as.integer(Year))

4.3 Animated Data Visualisation: gganimate methods

4.3.1 Building a static population bubble plot

ggplot(globalPop,
       aes(x = Old, y = Young,
           size = Population,
           colour = Country)) +
  geom_point(alpha = 0.7,
             show.legend = FALSE) +
  scale_colour_manual(values = country_colors) +
  scale_size(range = c(2, 12)) +
  labs(title = "Year: {frame_time}",
       x = "% Aged",
       y = "% Young")

4.3.2 Building the animated bubble plot

I add transition_time(Year) and ease_aes('linear').

p_anim <- ggplot(globalPop,
                 aes(x = Old, y = Young,
                     size = Population,
                     colour = Country)) +
  geom_point(alpha = 0.7,
             show.legend = FALSE) +
  scale_colour_manual(values = country_colors) +
  scale_size(range = c(2, 12)) +
  labs(title = "Year: {frame_time}",
       x = "% Aged",
       y = "% Young") +
  transition_time(Year) +
  ease_aes("linear")

p_anim

(Optional) If I want to render as GIF:

animate(p_anim, renderer = gifski_renderer())

4.4 Animated Data Visualisation: plotly

Both ggplotly() and plot_ly() can support animation by frame.

4.4.1 Building an animated bubble plot: ggplotly() method

gg <- ggplot(globalPop,
             aes(x = Old,
                 y = Young,
                 size = Population,
                 colour = Country)) +
  geom_point(aes(size = Population,
                 frame = Year),
             alpha = 0.7) +
  scale_colour_manual(values = country_colors) +
  scale_size(range = c(2, 12)) +
  labs(x = "% Aged",
       y = "% Young") +
  theme(legend.position = "none")

ggplotly(gg)

4.4.2 Building an animated bubble plot: plot_ly() method

bp <- globalPop %>%
  plot_ly(x = ~Old,
          y = ~Young,
          size = ~Population,
          color = ~Continent,
          sizes = c(2, 100),
          frame = ~Year,
          text = ~Country,
          hoverinfo = "text",
          type = "scatter",
          mode = "markers") %>%
  layout(showlegend = FALSE)

bp

4.5 Reference

• gganimate documentation
• plotly for R documentation